From bb26c5c1bdf7d561402cebd37a8d3ad09a604f85 Mon Sep 17 00:00:00 2001
From: Michael Lange <Michael.Lange@ecmwf.int>
Date: Thu, 11 Apr 2024 09:43:57 +0000
Subject: [PATCH] MaskedTransformer: Fix in-place rebuilding of scoped nodes

---
 loki/ir/transformer.py | 2 +-
 tests/test_visitor.py  | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/loki/ir/transformer.py b/loki/ir/transformer.py
index 140848bd6..4de3cfa11 100644
--- a/loki/ir/transformer.py
+++ b/loki/ir/transformer.py
@@ -485,7 +485,7 @@ def visit_ScopedNode(self, o, **kwargs):
 
         # Update rebuilt node
         if kwargs['parent_active']:
-            o._update(rebuilt)
+            o._update(*rebuilt)
             return o
         return tuple(i for i in rebuilt if i is not None) or None
 
diff --git a/tests/test_visitor.py b/tests/test_visitor.py
index 659542747..5fd9a941d 100644
--- a/tests/test_visitor.py
+++ b/tests/test_visitor.py
@@ -979,6 +979,14 @@ def test_masked_transformer_associates(frontend):
     assert len(FindNodes(Assignment).visit(body)) == 3
     assert not FindNodes(Associate).visit(body)
 
+    # Retains all nodes but the last, but check with ``inplace=True``
+    body = MaskedTransformer(start=None, stop=assignments[-1], active=True, inplace=True).visit(routine.body)
+    assert len(FindNodes(Assignment).visit(body)) == len(assignments) - 1
+    assocs = FindNodes(Associate).visit(body)
+    assert len(assocs) == 1
+    assert len(assocs[0].body) == len(assignments) - 1
+    assert all(isinstance(n, Assignment) for n in assocs[0].body)
+
 
 @pytest.mark.parametrize('frontend', available_frontends())
 def test_nested_masked_transformer(frontend):